stratified sample
representative sample
proportional sample

Instead, random samples, simple or stratified, are taken for the survey.

A jackknife variance estimator for unistage stratified samples with unequal probabilities.

These data were obtained from a stratified sample of firms.

Mapping was carried out on the 1:10,000 scale using a stratified sample of a thousand 1 km squares, 500 urban and 500 rural.

With few observations per reporting period and many scheduling constraints, a true stratified sample is not possible.

Inference from stratified samples: Second-order analysis of three methods for nonlinear statistics.

To avoid this possibility, we can opt for a stratified sample.

A cheaper method would be to use a stratified sample with urban and rural strata.

The quotas, combined over interviewers, thus form a non-random stratified sample.

An omnibus survey generally uses a stratified sample and can be conducted either by mail, telephone, or Internet.